Belt conveyors used in mining and mineral storage and other applications must often be provided with scrapers to clear the belt of material adhering to the conveyor surface; continuing accumulation of adherent material can ultimately lead to a maintenance shutdown or to damage to the expensive conveyor belt. The operating environment for a conveyor belt scraper is frequently quite hostile. Thus, working conditions are often wet, dirty, and even corrosive. Maintenance, a continuing necessity due to inevitable wear on the scraper, is often made difficult by limited access space. In a corrosive environment, blade maintenance and replacement problems are exacerbated by corrosion of mounting bolts, clamps, etc. These difficulties are prevalent in mining operations and in industrial applications as well.
Shock problems also have a major potential adverse effect on virtually any belt conveyor/scraper system. Large pieces of the conveyed material or debris adhering to the belt, when engaged by a scraper blade, can cause appreciable damage to the scraper blade or its support, or may even damage the expensive conveyor belt. Repeated shocks of this kind, or sometimes even a single major shock, may cause an expensive shutdown for repair or replacement of major system components, or both. Wherever possible, it is critically important to minimize or avoid any shock damage, as well as to compensate for the inevitable scraper wear due to continuing normal operation.
Scraper requirements, in a belt conveyor system, vary considerably. One scraper may be, and usually is, located at the head pulley. Indeed, two or more scrapers may be needed at the head pulley. Scrapers may also be located along the length of the belt between the head and tail pulleys. A linear scraper is the most common configuration, aligned normal to or at an acute angle to the path of the conveyor belt. But in some instances a V-shaped "plow" scraper will afford the best performance, whereas in others a staggered, overlapping arrangement for multiple scraper blades is most desirable.